Lead-acid batteries typically contain lead plates that are prepared by applying a lead paste to a metal grid and then drying the thus obtained plates. In order to absorb humidity from the lead paste and in order to ensure that the paste remains on the grid during the production process, a pasting paper is typically used as a support material. This paper is put under the grid and above the lead paste when the lead paste is laid down on the grid. The thereby finished lead plate is cut into appropriate sizes and dried and cured in ovens. Typically, a separator is inserted between two lead plates, thereby separating the plates in order to prevent a short-circuit between the plates during use in a lead-acid battery. This assembly can be placed into a cell of a battery thermoplastic container. The thermoplastic container is filled with sulphuric acid serving as an electrolyte and the battery thermoplastic container is closed with a cover.
Conventional pasting paper is made of natural fibres that will be disintegrated over time by the sulphuric acid. This leads to the formation of a gap between the lead plates or the lead plate and the separator (if present) that might cause erosion of the lead plate, in particular due to friction, thereby gradually deteriorating the performance of the battery.
Lead-acid batteries are typically used in vehicles as starter batteries. The automotive industry needs batteries with high life cycles due to the increased production of cars with environmental-friendly technology. Accordingly, there is a strong demand for higher life-cycle batteries. In particular, new technologies such as the “start and stop” technology, developed in order to save energy and to reduce the carbon dioxide emission, leads to an increased load for the lead-acid batteries because of the higher number of cycles of charge and discharge. Some of the cars having this new technology are still using conventional lead-acid batteries. Besides the conventional lead-acid batteries, absorptive glass mat (AGM) type batteries are known wherein the sulphuric acid electrolyte is immobilized between the lead plates. These AGM batteries have a better life cycle due to the pressure between separator and plate.
The life-cycle performances of floated lead-acid batteries are reduced because of the erosion of lead during the use. The erosion is in particular caused by friction and chemical reactions between the lead plates and the high temperature reached in the environment of the engine. Bad road conditions further decrease the life cycle of floated lead-acid batteries.
Conventional pasting paper used for lead-acid batteries are made of natural fibres that are dissolved in the sulphuric acid electrolyte. Because of this dissolution, conventional pasting paper has got no function in the battery itself.